To search or rummage through something; to dig or poke around looking for something of value, especially prospecting for gold or gems.
From Australian English, possibly from English dialect fossock or fusock, with uncertain ultimate origin. Became prominent in Australian gold-rush terminology in the 19th century.
Australian gold prospectors who fossicked on others' claims were originally called 'fossickers'—the term defined an entire class of treasure hunters who turned over riverbed rocks hoping to strike it rich!
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